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Societal Impact Statement Summary Conserving frankincense trees (Boswellia) is crucial for both ecological and socio‐economic reasons. Surveying these trees in the field and using remote sensing unmanned aerial vehicles in the Socotra Archipelago, we found that Socotran frankincense trees are threatened by forest fragmentation, overgrazing, and increasingly frequent extreme climate events. A better understanding of the distribution and the threats of these important insular species will improve the conservation policy of the local authorities and benefit local communities in the Socotra Archipelago. At the same time, this work serves as a good practice example to guide conservation efforts for other culturally important threatened tree species around the world, therefore helping to sustain local livelihoods, fostering ecological resilience, and supporting socio‐economic stability. Globally, frankincense trees (Burseraceae: Boswellia) are increasingly under threat because of habitat deterioration, climate impacts, and the olibanum trade. Despite harboring nearly half of the species in the genus, up‐to‐date insights are lacking for the insular endemic frankincense trees of the Socotra Archipelago UNESCO (United Nations Educational, Scientific and Cultural Organization) World Heritage Site (Yemen). We combined georeferencing of individual trees in the field with remote sensing applying unmanned aerial vehicles (UAVs) to evaluate Boswellia distribution and (sub)population sizes in the entire Socotra Archipelago. We counted 17,253 trees across all 11 taxa and we surveyed almost 55% directly in the field, collecting individual information on threats and health indicators. We estimate that the current total population sizes of the relatively common Socotran Boswellia taxa (Boswellia elongata, Boswellia popoviana, and Boswellia ameero) consist of a few thousand mature individuals with fragmented distribution of which a large proportion occurs in highly disjunct relictual stands, while the more range‐restricted species survive only through a few hundred (Boswellia nana and Boswellia samhaensis) to fewer than a hundred trees (Boswellia scopulorum). Our field data show that the Socotran frankincense trees are threatened by fragmentation and overgrazing resulting in a lack of natural regeneration, in combination with effects of extreme climate events (e.g., higher frequency and intensity of cyclones and prolonged drought) and potential future infrastructure developments; the species are less impacted by resin collection. We provide recommendations to strategize urgent protection of the declining Socotran frankincense trees, and we update their conservation status, resulting in an endangered status for seven and a critically endangered status for four taxa. [ABSTRACT FROM AUTHOR]

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The endemic Boswellia species (Burseraceae) on Socotra Island (Yemen) are of great local significance due to their various local ethnobotanical uses. However, despite the fact that these trees are endangered, little is known about their biology. We tested seed germination rates in controlled experiments (trials of 21 days) for two subsequent years and for nine endemic taxa of Boswellia occurring on Socotra Island. For this, seeds were collected island-wide from a wide range of localities and for several populations per species. We observed differences in germination among Boswellia species, among species and localities and among both years, which indicates that the development of seeds is strongly affected by external ecological factors. Although we noted a large variation in seed germination (relatively high in Boswellia socotrana), and half of the species showed relatively low mean daily germination, our study indicated that all endangered endemic Frankincense Tree taxa of Socotra harbor the potential for in situ conservation through recruitment, given that known impacts can be reduced in local replantation areas (e.g., grazing). [ABSTRACT FROM AUTHOR]

Background: Dracaena cinnabari is a monocot species that does not form annual tree rings; thus, its age can only be estimated. This species is threatened by low natural regeneration, with an evident absence of younger individuals most likely caused by overgrazing; therefore, knowing trees’ ages is important for possible conservation strategies; Methods: Data collection was conducted on the Firmihin Plateau on Socotra Island (Yemen) in 2021, and the diameter at breast height (DBH) of 1077 individuals was measured, the same as those established on monitoring plots 10 years before the current measurement. The 10-year radial stem increment and DBH obtained in 2011 served as a basis for the linear model from which the equations for the age calculation were derived. Results and Conclusions: A direct model of age estimation for D. cinnabari was developed. According to the fit model, the age in the first (10.1–15 cm) DBH class was estimated to be 111 years, while that in the last DBH class (90.1–95 cm) was estimated to be 672 years. The results revealed that the previously used indirect methods for D. cinnabari age estimation were accurate.

The endemic Boswellia species (Burseraceae) on Socotra Island (Yemen) are of great local significance due to their various local ethnobotanical uses. However, despite the fact that these trees are endangered, little is known about their biology. We tested seed germination rates in controlled experiments (trials of 21 days) for two subsequent years and for nine endemic taxa of Boswellia occurring on Socotra Island. For this, seeds were collected island-wide from a wide range of localities and for several populations per species. We observed differences in germination among Boswellia species, among species and localities and among both years, which indicates that the development of seeds is strongly affected by external ecological factors. Although we noted a large variation in seed germination (relatively high in Boswellia socotrana), and half of the species showed relatively low mean daily germination, our study indicated that all endangered endemic Frankincense Tree taxa of Socotra harbor the potential for in situ conservation through recruitment, given that known impacts can be reduced in local replantation areas (e.g., grazing).

This article summarises the major environmental and social justice issues facing Yemen, with a discussion of climate change, the impact of the war, oil extraction practices and water use. It also includes two brief case studies as examples of the impact of these issues in worsening inequality: first, the series of disastrous floods in 2020 and, second, the situation in Soqotra. [ABSTRACT FROM AUTHOR]

The relationship of two geographically and ecologically separated populations of Turraea socotrana Styles and F. White (Meliaceae), a vulnerable and scattered shrub from the island of Socotra (Yemen), was explored using preliminary molecular data. The nuclear ribosomal ITS region was used to screen the level of genetic divergence of T. socotrana from ecologically distant localities in comparison to a few other species of Turraea and closely related genera. The individuals from the inland (Diksam) differed from the western coastal ones (Ma'alah) by vegetative characters and by the rbcL gene. This may be due to the fact that the population from Ma'alah grows on lithosoil slopes directly exposed to moist winds coming from the sea, whereas the population of Diksam occurs on arid cliffs overlooking the inland of the island. The ITS sequences grouped the studied populations from Socotra together and separated them from other species of Turraea that are morphologically similar and occurring in East Africa. Considering the differences recorded in the rbcL gene, we suggest that the populations of T. socotrana investigated here on only a few specimens from two different areas on the island, deserve more research. Our preliminary study potentially indicates that there may be independent evolutionary significant units in this species, however, more research including a wider sampling and comparison to other taxa is needed. [ABSTRACT FROM AUTHOR]

The importance of populations of the Socotra dragon's blood trees (Dracaena cinnabari Balf.f., 1882) for horizontal precipitation capture was estimated for the first time. Dragon's blood trees (Asparagaceae) inhabit semiarid cloud forests with low levels of rainfall that strongly depend on additional moisture from fog and clouds. Our estimation was based on a detailed description of the aboveground biomass structure of stands of the dragon's blood trees on Socotra Island. The aboveground biomass was described using non-destructive methods. An example of a well-preserved forest was measured in terms of the basic biometric characteristics of each tree, and the trees were divided into three classes based on crown projections. For each class, we took detailed measurements of one representative tree. All measured and counted growth characteristics were converted to the stand level. The tree population at the whole island level was investigated using remotely sensed data. The estimation of horizontal precipitation was performed using detailed and precise evaluation of the available climate data in half-hour intervals over the period of June 2009 and June 2010 and the ambulatory direct measurements (12.6.2009–26.6.2009). The mean annual horizontal precipitation below the crown of the dragon's blood tree was estimated to be 792 mm in the highest (951–1545 m a.s.l.), 373 mm in the middle (601–950 m a.s.l.) and 46 mm in the lowest (180–600 m a.s.l.) altitudinal zones. Our model showed that the horizontal precipitation exceeded 40% of the total annual precipitation. The decline in the dragon's blood tree forest could therefore cause the loss of additional water from the island's hydrological cycle. [ABSTRACT FROM AUTHOR]

This article presents the methodological approach of age estimation of juvenile Socotra dragon's blood trees (Dracaena cinnabari Balf. F., DBT) for the first time. To date, only the model for the age estimation of the tree crown after the first flowering event has been published. The DBTs were measured on Socotra Island (Yemen), on the Firmihin Plateau. A set of three indirect growth models was used for the estimation of the juvenile phase duration. The first model shows the relationship between the proportion of stem cavities and diameter at breast height (DBH). The second model describes the relationship between the DBH and stem height of juvenile trees. The third model expresses the radial stem increment with an increasing number of branch orders. The first model estimates the ratio of the stem cavity and secondary vascular tissue. The second model serves to retrospectively estimate the DBH of the tree at the time of the first flowering event according to the height of the stem. Extrapolation of the third model enabled us to estimate the duration of the juvenile phase that corresponds to the thickness of the secondary vascular tissue. A non-destructive methodology for juvenile DBT age estimation was developed, although the calculated absolute values are not precise. The same approach can also be used for the other arborescent dragon tree species. The validity of our assumption should be verified by repeated measurements on trees from different age groups. And thus, more precise model with less uncertainty about the parameter estimates could be obtained in the future. [ABSTRACT FROM AUTHOR]

The article investigates the thematic and stylistic parallelism between Old Testament books (primarily, but not exclusively, Proverbs, Ecclesiastes, and the Song of Songs) and the oral poetry in the Modern South Arabian language Soqotri. Striking similarities between the two corpora, noted already by the father of Soqotri studies in the West, David Heinrich Müller, are investigated in depth on the basis of the author's fieldwork experience on the island. [ABSTRACT FROM AUTHOR]

Dragon's blood tree, a flagship endemic species of Socotra, is threatened with extinction due to lack of natural regeneration, likely because of goat herbivory and/or climatic factors. Loss of dragon's blood tree would result in loss of other native flora, heightening the importance of formulating a conservation strategy for it. Although artificial afforestation might be used to offset the lack of natural regeneration, it would have to overcome the same threats faced by naturally occurring seedlings. Moreover, there is no published information on the growth dynamics of seedlings in plantations in situ on Socotra. To fill this information gap, we compared seedling growth (total plant height, leaves number, stem height, stem diameter) over an 8-year period after planting at three sites that differed in the degree to which goats were excluded and in whether they were watered regularly over the period. In addition to developing a new classification of the growth stages, which will enable better tracking of population dynamics, we found that continuous goat exclusion was necessary to prevent seedling mortality. Also, although seedling growth overall was slow, growth parameters of regularly irrigated seedlings ranged from 156% to 446% of those not regularly watered, suggesting that this treatment can speed seedlings' escape from goat browsing. For the dragon's blood tree and likely for other taxa within this group, extremely slow growth and long generation times suggest that conservation and restoration efforts will require a commitment to active management that will last decades, rather than a short-term approach. [ABSTRACT FROM AUTHOR]

For the first time, in situ field measurements of sap flow were conducted in adult Dracaena cinnabari plant native to the arid tropical climate of Socotra Island. The heat field deformation (HFD) method was applied using both single and multi-point sensors to study azimuthal and radial sap flow variability in stem, roots and first-order branches over two weeks during a winter monsoon. The main aim of this work was to monitor sap flow in adult D. cinnabari in-situ to better understand its physiological adaptation to extreme arid environments. The second aim was to compare our results with earlier sap flow measurements in adult D. draco uing the same HFD method. The last question we wanted to answer was comparison of sap flow measurements in both, young and adult Dracaena species. We found that sap flow magnitude is low and of a similar range in all observed D. species. High sap flow variability was recorded in different parts of adult D. cinnabari plant which changed throughout the day responding to interplay between intrinsic and extrinsic water potential gradients induced by sunlight. Maximum sap flow levels had variable pattern around stem in response to sun exposure, similarly as it was observed in adult D. draco plant. Sensors installed tangentially in stem xylem showed that water transport in adult D. cinnabari may move in lateral direction. This work also presents several methodological aspects detected from earlier observations of dicots which proved to be more pronounced in adult D. species. These methodologies relate to interpreting negative sap flow rates in conjunction with established axial flow reversal during hydraulic redistribution usually occurring under low evaporative demands and dry soil. Conversely, flow reversal during the day under high evaporative demands and wet soil may designate lateral water movement induced by internal water redistribution. [ABSTRACT FROM AUTHOR]

During ongoing archaeological fieldwork on Soqotra, Yemen, by the Soqotra Heritage Project, a poorly recorded rock art site on the north coast of the island was identified and documented. A systematic survey of this rock art site has revealed an extensive corpus of 187 rock art motifs that include feet, cupules, a ship, various geometric patterns, and cruciform shapes that bear striking similarities to motifs found in other rock art sites throughout the island. This site is now known to be the second largest petroglyph site found on Soqotra. Unfortunately, the entire site is currently under imminent threat from development. [ABSTRACT FROM AUTHOR]

The pure Soqotri resin of Dracaena cinnabari Balf.f. (Dracaenaceae) has no volatile smell due to its low content of volatile constituents. Although it is insoluble in n-Hexane, we found that the resin, when suspended in n-Hexane within five days at 5 °C, led to the extraction of a small portion of a single volatile liquid constituent, which was identified by GC-MS as sesquiterpene β-caryophyllene. This method of extracting the volatile constituents using hexane under cooling is very suitable for resins of the Dracaena species because these resins usually contain very few volatile terpenes and/or non-terpenes, and they may contain only one volatile terpene per resin as this study result. β-Caryophyllene was identified and separated for the first time from the Soqotri standard resin of Dracaena cinnabari. Therefore, β-caryophyllene, as a new chemical property, can support to evaluate the purity of the Soqotri resin. Moreover, a big mass of D. cinnabari resin can yield concentrated β-caryophyllene as a liquid extract for further pharmaceutical and nutraceutical applications.

This article depicts the initial human-environmental relations that prevailed during the pre-modern period of Soqotra’s history prior to its incorporation into a state-led modernization process and its subsequent enclosure within a United Nations-designed conservation zoning plan and ecotourism economy. The term ecological primordialism is coined to highlight the primacy of the environment as the enabling and constraining context for the constitution of the Soqotran community. It entails a symbiotic relationship between an ecosystem and a human social system, which structured the contingent relations between the raw materials for livelihood making and community formation: people, resources and space. The article elucidates how Soqotrans managed this mostly constraining human-environment nexus through a series of adaptive practices: their taxonomic appropriation and practical domestication of the island’s environmental resources; their transformation of the landscape into a domain of livelihood; their organization of dispersed settlements into a socio-political unit; their demarcation of the island into geographical zones of cultural differentiation; and their establishment of mutual aid institutions that simultaneously regulated resource use while integrating all islanders into relations of social kinship. The article concludes with a cautionary tale about the use of anachronistic human-environment relations as the basis of conservation policy. [ABSTRACT FROM AUTHOR]

The authors discuss some characteristic aspects of the culture of the island of Soqotra, located in the Indian Ocean, 400 Km from the coast of Yemen and the main island of a small archipelago that looks like the natural extension of the Horn of Africa. The geo-physical configuration of the island provides for a great variety of climates; consequently, its flora is extremely rich and it includes an impressive percentage of endemic species. The main source of sustenance for the Soqotri population is goat farming, since the land is not suitable for agriculture; fishing has become increasingly important after the construction of paved roads and the diffusion of modern means of transport, thus reducing the distance between coast and inland areas. Wild plants have always been very important for the survival of the inhabitants of Soqotra, who used them as remedies for both people and animals. This central role of plants is reflected in the botanical knowledge of the islanders: the different uses of plants are well known and plants that have the same uses share the same name. In the past commercial trading was extremely developed; historically trade linked Soqotra with the Horn of Africa, Egypt, Rome and India. In more modern times the commercial importance of the island stems from its strategical position in the Indian Ocean. Not only goods moved, but people too. The case of the Soqotra fishermen is often cited as an example: some of them are the descendants of ancient African settlers. Even the Soqotri language, now endangered, tells a story of ancient contacts.

The paved (tarmac) roads had been constructed on Soqotra island over the last 15 years. The vegetation along the roads was disturbed and the erosion started immediately after the disturbance caused by the road construction. Our assumption is that biotechnical measurements should prevent the problems caused by erosion and improve stabilization of road edges. The knowledge of plant species which are able to grow in unfavourable conditions along the roads is important for correct selection of plants used for outplanting. The vegetation succession was observed using phytosociological relevés as a tool of recording and mapping assambblages of plants species along the roads as new linear structures in the landscape. Data from phytosociological relevés were analysed and the succession was characterised in different altitudes. The results can help us to select group of plants (especially shrubs and trees), which are suitable to be used as stabilizing green mantle in various site conditions and for different purposes (anti-erosional, ornamental, protection against noise or dust, etc.).

Leucas virgata Balf.f. (Lamiaceae) was collected from the Island Soqotra (Yemen) and its essential oil was obtained by hydrodistillation. The chemical composition of the oil was investigated by GC and GC-MS. Moreover, the essential oil was evaluated for its antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria, and one yeast species by using broth micro-dilution assay for minimum inhibitory concentrations (MIC) and antioxidant activity by measuring the scavenging activity of the DPPH radical. The investigation led to the identification of 43 constituents, representing 93.9% of the total oil. The essential oil of L. virgata was characterized by a high content of oxygenated monoterpenes (50.8%). Camphor (20.5%) exo-fenchol (3.4%), fenchon (5.4%), and borneol (3.1%) were identified as the main components. Oxygenated sesquiterpenes were found as the second major group of compounds (21.0%). β-Eudesmol (6.1%) and caryophyllene oxide (5.1%) were the major compounds among oxygenated sesquiterpenes. The results of the antimicrobial assay showed that the oil exhibited a great antibacterial activity against the tested S. aureus, B. subtilis, and E. coli. No activity was found against P. aeruginosa and C. albicans. Moreover, the DPPH-radical scavenging assay exhibited only a moderate antioxidant activity (31%) for the oil at the highest concentration tested (1 mg/mL).

This paper presents a comprehensive review of historical and current rock art research on the island of Soqotra, Yemen and places these sites within a spatial framework from which it analyses themes concerning water and the visibility and invisibility of these sites within the broader landscape. The analysis of these sites shows how water was of fundamental importance to the indigenous inhabitants over the longue durée. It also highlights how rock art has not only been able to reinforce the ethnographic and historical accounts of the indigenous inhabitants, but also strengthen our temporal knowledge of the social and cultural lives of the inhabitants of Soqotra.

Woody vegetation dynamics and Dracaena cinnabari regeneration have been studied for five years in the conditions of Socotra Island. Woody plants were measured regularly inside and outside the exclosure area, and the growth and survival of D. cinnabari seedlings were observed. In the exclosure of about 1000 m 2 a total of 49 species were identified, including 23 endemics, growing in the average density of 3.82 specimens per m 2 . The fenced area was overgrown relatively rapidly by dense grass cover – reaching approx. 2.7 t/ha. Species growth dynamics inside and outside the exclosure shows that grazing had a marked impact, leading to the elimination of trees and shrubs. All grazed species grew noticeably in the exclosure, in the average of 50 cm in 5 years. D. cinnabari as the dominant flagship species of Socotra has been studied with regards to regeneration dynamics. Observations indicate that probability of its seedlings survival increases with their age. No seedlings germinated from the seeds sown in the experiment, however, outplanted seedlings performed relatively well. Field observations show that D. cinnabari seed germination is triggered when the seed reaches a protected micro-habitat with a developed humus layer and high relative humidity in the soil lasts for at least two days. [ABSTRACT FROM AUTHOR]

Malaria, leishmaniasis and human African trypanosomiasis continue to be major public health problems in need of new and more effective drugs. The aim of this study was to evaluate in vitro antiprotozoal activity of twenty endemic medicinal plants collected from the island of Soqotra in the Indian Ocean. The plant materials were extracted with methanol and tested for antiplasmodial activity against erythrocytic schizonts of Plasmodium falciparum, for antileishmanial activity against intracellular amastigotes of Leishmania infantum and for antitrypanosomal activity against intracellular amastigotes of Trypanosoma cruzi and free trypomastigotes of T. brucei. To assess selectivity, cytotoxicity was determined against MRC-5 fibroblasts. Selective activity was obtained for Punica protopunica against Plasmodium (IC50 2.2 µg/mL) while Eureiandra balfourii and Hypoestes pubescens displayed activity against the three kinetoplastid parasites (IC50 < 10 µg/mL). Acridocarpus socotranus showed activity against T. brucei and T. cruzi (IC50 3.5 and 8.4 µg/mL). Ballochia atrovirgata, Dendrosicycos socotrana, Dracaena cinnabari and Euphorbia socotrana displayed non-specific inhibition of the parasites related to high cytotoxicity.

Dracaena cinnabari Balf. f. (Dracaenaceae) is an important plant endemic to Soqotra Island, Yemen. Dragon’s blood (Dam Alakhwin) is the resin that exudes from the plant stem. The ethnobotanical survey was carried out by semi-structured questionnaires and open interviews to document the ethnobotanical data of the plant. According to the collected ethnobotanical data, the resin of D. cinnabari is widely used in the traditional folk medicine in Soqotra for treatment of dermal, dental, eye and gastrointestinal diseases in humans. The resin samples found on the local Yemeni markets were partly or totally substituted by different adulterants. Organoleptic properties, solubility and extractive value were demonstrated as preliminary methods to identify the authentic pure Soqotri resin as well as the adulterants. In addition, the resin extracts and its solution in methanol were investigated for their in vitro antifungal activities against six human pathogenic fungal strains by the agar diffusion method, for antioxidant activities using the DPPH assay and for cytotoxic activity using the neutral red uptake assay. The crude authentic resin dissolves completely in methanol. In comparison with different resin extracts, the methanolic solution of the whole resin showed the strongest biological activities. It showed strong antifungal activity, especially against Microsporum gypseum and Trichophyton mentagrophytes besides antioxidant activities and toxicity against FL-cells. These findings confirm and explain the traditional uses of the resin for the treatment of skin diseases and mouth fungal infections.

The barks of two endemic Commiphora species namely, Commiphora ornifolia (Balf.f.) Gillett and Commiphora parvifolia Engl., were collected from Soqotra Island in Yemen and their essential oils were obtained by hydrodistillation. The chemical composition of both oils was investigated by GC and GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and one yeast species by using a broth micro-dilution assay for minimum inhibitory concentrations (MIC) and for their antioxidant activity by measuring the DPPH radical scavenging activity. A total of 45 constituents of C. ornifolia (85.6%) and 44 constituents of C. parvifolia (87.1%) were identified. The oil of C. ornifolia was characterized by a high content of oxygenated monoterpenes (56.3%), of which camphor (27.3%), α-fenchol (15.5%), fenchone (4.4%) and borneol (2.9%) were identified as the main components. High contents of oxygenated sesquiterpenes (36.1%) and aliphatic acids (22.8%) were found in C. parvifolia oil, in which caryophyllene oxide (14.2%), β-eudesmol (7.7%), bulnesol (5.7%), T-cadinol (3.7%) and hexadecanoic acid (18.4%) predominated. The results of the antimicrobial assay showed that both oils exhibited moderate to high antibacterial activity especially against Gram-positive bacteria. C. ornifolia oil was the most active. In addition, the DPPH-radical scavenging assay exhibited only weak antioxidant activities for both oils at the high concentration tested.

Leucas virgata Balf.f. (Lamiaceae) was collected from the Island Soqotra (Yemen) and its essential oil was obtained by hydrodistillation. The chemical composition of the oil was investigated by GC and GC-MS. Moreover, the essential oil was evaluated for its antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria, and one yeast species by using broth micro-dilution assay for minimum inhibitory concentrations (MIC) and antioxidant activity by measuring the scavenging activity of the DPPH radical. The investigation led to the identification of 43 constituents, representing 93.9% of the total oil. The essential oil of L. virgata was characterized by a high content of oxygenated monoterpenes (50.8%). Camphor (20.5%) exo-fenchol (3.4%), fenchon (5.4%), and borneol (3.1%) were identified as the main components. Oxygenated sesquiterpenes were found as the second major group of compounds (21.0%). ß-Eudesmol (6.1%) and caryophyllene oxide (5.1%) were the major compounds among oxygenated sesquiterpenes. The results of the antimicrobial assay showed that the oil exhibited a great antibacterial activity against the tested S. aureus, B. subtilis, and E. coli. No activity was found against P. aeruginosa and C. albicans. Moreover, the DPPH-radical scavenging assay exhibited only a moderate antioxidant activity (31%) for the oil at the highest concentration tested (1 mg/mL). [ABSTRACT FROM AUTHOR]

The prevailing geopolitical relations between parts of the world have always provided the enabling matrix of anthropological practice. Given the emerging global power alternation and its reconfiguration of the political and epistemic relations between regions of the world, which I call a postexotic historical conjuncture, anthropology must recalibrate its practices. This article suggests 5 domains of disciplinary adjustment: First, the reconceptualization of our metageographic imagination from one that assumes hierarchical relations to one of horizontal or radial relations between the world’s regions. Second, the abandonment of an egocentric intellectual sensibility in favor of a sociocentric one, as orientation to fieldwork. Third, the disassociation of fieldwork as a distinctive research practice from ethnography. Fourth, the substitution of mesography for ethnography as an alternative approach to inquiry for a postexotic anthropology. And fifth, the adoption of an ethic of reciprocity as a remedy to the chronic unequal exchange between anthropologists and communities. [ABSTRACT FROM PUBLISHER]

Malaria, leishmaniasis and human African trypanosomiasis continue to be major public health problems in need of new and more effective drugs. The aim of this study was to evaluate in vitro antiprotozoal activity of twenty endemic medicinal plants collected from the island of Soqotra in the Indian Ocean. The plant materials were extracted with methanol and tested for antiplasmodial activity against erythrocytic schizonts of Plasmodium falciparum, for antileishmanial activity against intracellular amastigotes of Leishmania infantum and for antitrypanosomal activity against intracellular amastigotes of Trypanosoma cruzi and free trypomastigotes of T. brucei. To assess selectivity, cytotoxicity was determined against MRC-5 fibroblasts. Selective activity was obtained for Punica protopunica against Plasmodium (IC50 2.2 μg/mL) while Eureiandra balfourii and Hypoestes pubescens displayed activity against the three kinetoplastid parasites (IC50 < 10 μg/mL). Acridocarpus socotranus showed activity against T. brucei and T. cruzi (IC50 3.5 and 8.4 μg/mL). Ballochia atrovirgata, Dendrosicycos socotrana, Dracaena cinnabari and Euphorbia socotrana displayed non-specific inhibition of the parasites related to high cytotoxicity. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, the two endemic Soqotraen plants Boswellia elongata and Jatropha unicostata were investigated for their anti-inflammatory, antinociceptive and antioxidant potential. To assess the anti-inflammatory and antinociceptive activities, two concentrations of each extract (200 and 400mg/kg, p.o.) were tested in carrageenan-induced rat paw edema, cotton pellet granuloma in rats, acetic acid-induced abdominal writhing and hot-plate test model in mice. Moreover, the antioxidant activity was determined in vitro, using scavenging activity of DPPH radical and β-carotene–linoleic acid assays. Both plants produced significant (P <0.05–0.01) anti-inflammatory and antinociceptive effects; however the results suggest that B. elongata possesses the highest activities. B. elongata and J. unicostata at (400mg/kg) reduced the paw edema considerably (82% and 53%) and the weight of cotton pellet granuloma (51% and 32%), respectively. Furthermore, they diminished the abdominal constriction induced by acetic acid with a 67% and 41% inhibition respectively, and prolonged significantly the reaction time of animal with relatively extended duration of stimulation. In addition, both plants showed considerable antioxidant activity in both assays. These results clearly confirmed the traditional anti-inflammatory indication of B. elongata and suggest that B. elongata could be a potential source for anti-inflammatory, antinociceptive and antioxidant agents. [Copyright &y& Elsevier]

Abstract: The chemical composition of three essential oils obtained from the barks of three endemic Boswellia species namely, Boswellia dioscorides, Boswellia elongata and Boswellia socotrana which were collected from the Soqotra Island (Yemen), was investigated. In parallel to that evaluation of their antimicrobial and antioxidant activities was also carried out. The investigation led to the identification of 72, 70 and 67 constituents for B. dioscorides, B. elongata, and B. socotrana, respectively. The B. dioscorides oil was found to have a high content of monoterpene hydrocarbons (32.8%) with α-thujene (9.3%) and α-pinene (8.3%) as main components. Whereas, the essential oil of B. elongata was characterised by high diterpene content (31.7%), in which incensol (14.8%) was found to be the major constituent. On the other hand, the oil obtained from the B. socotrana was found to be predominated of monoterpene hydrocarbons (26.4%) and oxygenated monoterpenes (30.7%) with p-cymene (13.0%), 2-hydroxy-5-methoxy-acetophenone (16.3%) and camphor (11.6%). All essential oils possessed antimicrobial activity especially against Gram-positive bacteria with MIC-values between 1.8 and 17.2mg/ml. Furthermore, the DPPH-radical scavenging assay exhibited only weak antioxidant activities (28%) at 1.0mg/ml. [ABSTRACT FROM AUTHOR]

The barks of two endemic Commiphora species namely, Commiphora ornifolia (Balf.f.) Gillett and Commiphora parvifolia Engl., were collected from Soqotra Island in Yemen and their essential oils were obtained by hydrodistillation. The chemical composition of both oils was investigated by GC and GC-MS. Moreover, the essential oils were evaluated for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and one yeast species by using a broth micro-dilution assay for minimum inhibitory concentrations (MIC) and for their antioxidant activity by measuring the DPPH radical scavenging activity. A total of 45 constituents of C. ornifolia (85.6%) and 44 constituents of C. parvifolia (87.1%) were identified. The oil of C. ornifolia was characterized by a high content of oxygenated monoterpenes (56.3%), of which camphor (27.3%), α-fenchol (15.5%), fenchone (4.4%) and borneol (2.9%) were identified as the main components. High contents of oxygenated sesquiterpenes (36.1%) and aliphatic acids (22.8%) were found in C. parvifolia oil, in which caryophyllene oxide (14.2%), β- eudesmol (7.7%), bulnesol (5.7%), T-cadinol (3.7%) and hexadecanoic acid (18.4%) predominated. The results of the antimicrobial assay showed that both oils exhibited moderate to high antibacterial activity especially against Gram-positive bacteria. C. ornifolia oil was the most active. In addition, the DPPH-radical scavenging assay exhibited only weak antioxidant activities for both oils at the high concentration tested. [ABSTRACT FROM AUTHOR]

Soqotra Island, the remote border outpost of the Yemeni state in the Indian Ocean, is a community of mixed ethnic composition with a non-Arabic mother tongue. It offers an ideal socio-political context for the study of state-community relations in terms of polity formation as part of a political incorporation process. This focus provides a corrective to the still dominant segmentary society paradigm and its tribes-driven state politics in the anthropological discourse on Yemen. Polity formation in Soqotra occurred through a series of acts of political incorporation by a succession of political regimes from the late nineteenth century to the present. The study of this process is pursued through a historical narrative of the state's politics of administration. This narrative is aptly described as a mesography, as its analytical focus is on the meso-level institutional web of four different political regimes with their distinctive modes of polity regimentation and their structuring effects on Soqotrans' communal life. [ABSTRACT FROM AUTHOR]

Limonium guigliae, from the island of Soqotra (Yemen) is described. This new species, close to L. paulayanum differs from it by its size, flower morphology and ecology. [ABSTRACT FROM AUTHOR]

Age determination of tropical trees, and monocotyledons in general, is not an easy task. Representatives of the Dracaena genus have survived in woodlands on dry margins of the Tethys tropical forest since the Tertiary Period. Here we present analyses of Dracaena cinnabari (DC) stand dynamics via direct and indirect methods of age determination. The direct method has taken advantage of historical photographs of DC mountain woodlands from Soqotra during an Austrian scientific expedition in 1899 by comparing these with the woodland stage in 2004. A decline in the number of tree individuals is obvious, but considering the little that is known about dynamics of DC woodland, one cannot simply state that such decline means forest destruction. The results from this direct method are compared to an indirect mathematical method of age determination using data from 2003. Indirect age determination values differed only about 6.5% from those obtained with the direct method, indicating that the indirect methodology is quite precise. [Copyright &y& Elsevier]

The major constituents of the essential oil obtained by hydrodistillation from the oleogum resin of Commiphora kua Vollesen were identified by GC-MS. Sixteen constituents were detected from the essential oil, which constituted about (90.5%) of the total amount. Major constituents of the oil were γ- cadinol (33.0%), g-cadinene (22.5%), δ-cadinene (17.0%), isocaryophyllene (3.7%), allo-aromadendrene (2.8%), α-muurolene (2.7%), and α-humulene (2.4%). The Oil of Commiphora kua showed moderate antifungal activity against Cladosporium cucumerinum. [ABSTRACT FROM AUTHOR]

The chemical composition, antioxidant and anticholinesterase activity of three essential oils (EOs) obtained from the oleogum resin of three endemic Sqotraen Boswellia species, Boswellia socotrana Balf. f, Boswellia ameero Balf. f, and Boswellia elongata Balf. f were determined. GC-MS technique was used for the analysis of the oils. Oils of B. socotrana and B. ameero were characterized by a high content of monoterpenes. The main constituens of B. socotrana and B. ameero were (E)-2,3-epoxycarene (51.8%), 1,5-isopropyl-2-methylbicyclo[3.1.0]hex-3-en-2-ol (31.3%), and α-cymene (7.1%); (3E,5E)-2,6-dimethyl-1,3,5,7-octatetraene (34.9%), 1-(2,4-Dimethylphenyl)ethanol (20.3%), 3,4-dimethylstyrene (17.3%), α-campholenal (13.4%) and α-terpineol (12.4%) respectively. The composition of B. elongata oil was dominated by the diterpene verticiol (52.4%), the sesquiterpene caryophellene (39.1%) and methylcycloundecanecarboxylate (7.8%). The oils were screened for their antioxidant activity by using the DPPH free radical scavenger assay and their anticholinesterase activity on acetylcholinesterase enzyme by using in vitro Ellman method. The antioxidant activity of EOs from B. socotrana (IC50 =121.4 μg/mL) appeared to be more potent than that of B. elongata (IC50 =211.2 μg/mL) and B. ameero (IC50 =175.2 μg/mL). EO of B. socotrana showed the higher AChE inhibitory activity with 59.3% at concentration of 200 μg/mL in comparison to EOs of B. elongata and B. ameero (29.6, 41.6 enzyme inhibition) respectively. [ABSTRACT FROM AUTHOR]

Abstract: Twenty-five selected plants belonging to 19 families were collected from different localities of the island Soqotra, dried and extracted with the solvents chloroform, methanol and hot water to yield 80 extracts. The extracts were tested for their antimicrobial activity against several Gram-positive and Gram-negative bacteria and against one yeast species using agar diffusion method. Antibacterial activity was demonstrated especially against Gram-positive bacteria including multiresistant Staphylococcus strains. The greatest activity was exhibited by the methanolic extracts of Boswellia elongata, Boswellia ameero, Buxus hildebrandtii, Commiphora parvifolia, Jatropha unicostata, Kalanchoe farinacea, Pulicaria stephanocarpa, Punica protopunica, Withania adunensis and Withania riebeckii. Only the methanolic extract of Buxus hildebrandtii displayed significant antifungal activity. [Copyright &y& Elsevier]

The pure Soqotri resin of Dracaena cinnabari Balf.f. (Dracaenaceae) has no volatile smell due to its low content of volatile constituents. Although it is insoluble in n-Hexane, we found that the resin, when suspended in n-Hexane within five days at 5 °C, led to the extraction of a small portion of a single volatile liquid constituent, which was identified by GC-MS as sesquiterpene β-caryophyllene. This method of extracting the volatile constituents using hexane under cooling is very suitable for resins of the Dracaena species because these resins usually contain very few volatile terpenes and/or non-terpenes, and they may contain only one volatile terpene per resin as this study result. β-Caryophyllene was identified and separated for the first time from the Soqotri standard resin of Dracaena cinnabari. Therefore, β-caryophyllene, as a new chemical property, can support to evaluate the purity of the Soqotri resin. Moreover, a big mass of D. cinnabari resin can yield concentrated β-caryophyllene as a liquid extract for further pharmaceutical and nutraceutical applications. [ABSTRACT FROM AUTHOR]

The ethnobotanical survey of Euclea divinorum Hiern (Ebenaceae) was conducted on Soqotra Island, Yemen. The root bark is used to treat mouth, dental, dermal and blood diseases in the traditional medicine of the island. The study is the first report about the effect of the plant root barks against six human pathogenic fungi. The non-polar dichloromethane extract of Euclea divinorum root bark showed stronger antifungal activities compared to polar direct and sequential methanolic extracts. These extracts showed significant broad antifungal activity against Absidia corymbifera, Aspergillus fumigatus, Candida krusei, Microsporum gypseum, Mucor sp. and Trichophyton mentagrophytes compared to the standard antibiotic drug nystatin. Thin-layer chromatography (TLC) revealed the presence of the naphthoquinones in the extracts. The results showed an extraction process to separate most antifungal naphthoquinones from the root bark by using non-polar solvent dichloromethane, while flavonoids remained in the polar methanolic extracts; therefore, the polar sequential and direct methanolic extracts recorded higher antioxidant activity than the non-polar extracts with less toxicity. The biological and chemical results identified the presence of antifungal and antioxidant constituents in the root bark and confirm its traditional use in Soqotra Island as crude powder to treat dental and dermal diseases and to clean teeth. Moreover, our results are compared with literature review on ethnobotany and phytopharmacology of E. divinorum to present a medicinal monograph about the plant. [ABSTRACT FROM AUTHOR]

Unsustainable overgrazing is one of the most important threats to the endemic and endangered population of dragon's blood tree (Dracaena cinnabari) on Socotra Island (Republic of Yemen). However, there is a lack of information about the exact population size and its conservation status. We estimated the population size of D. cinnabari using remote sensing data. The age structure was inferred using a relationship between crown projection area and the number of branch sections. The conservation importance of each sub-population was assessed using a specially developed index. Finally, the future population development (extinction time) was predicted using population matrices. The total population size estimated consists of 80,134 individuals with sub-populations varying from 14 to 32,196 individuals, with an extinction time ranging from 31 to 564 years. Community forestry controlled by a local certification system is suggested as a sustainable land management approach providing traditional and new benefits and enabling the reforestation of endemic tree species on Socotra Island. [ABSTRACT FROM AUTHOR]